A remote operation system is known which remotely operates a user terminal, such as a mobile telephone terminal, from a support terminal (see, for example, Patent Literature 1). With the use of a remote operation system, setting and operations of a user terminal (e.g., mobile telephone terminal, personal computer and the like) or an application program installed in the user terminal can be performed from the support terminal which is remotely located. Accordingly, a remote operation system can be used for a remote support in which an operator remotely located supports a user who is not familiar with operations of a mobile telephone terminal, a personal computer or the like. The term “remote operation” in this specification includes performing an input operation on a remote terminal which is remotely located, monitoring a display screen of a remote terminal which is remotely located, changing setting of a remote terminal which is remotely located, or transferring data to a memory of a remote terminal which is remotely located.
In the remote support, in order to allow a remote operation of a user terminal from an operator who is remotely located (hereinafter referred to as a supporter), a procedure to authenticate the supporter by a user is used. In this authentication procedure, the user is required to operate the user terminal to input information for authenticating the supporter, and to transmit this information to a server. This procedure for authenticating the supporter by the user is to ensure security for preventing such a situation in which an unspecified third party remotely operates the user terminal.